U.S. patent application number 15/493619 was filed with the patent office on 2018-03-08 for multilayer ceramic electronic component and method of manufacturing the same.
The applicant listed for this patent is SAMSUNG ELECTRO-MECHANICS CO., LTD.. Invention is credited to Jae Yeol CHOI, Ki Pyo HONG, Yong PARK, Jin Yung RYU.
Application Number | 20180068795 15/493619 |
Document ID | / |
Family ID | 61281675 |
Filed Date | 2018-03-08 |
United States Patent
Application |
20180068795 |
Kind Code |
A1 |
PARK; Yong ; et al. |
March 8, 2018 |
MULTILAYER CERAMIC ELECTRONIC COMPONENT AND METHOD OF MANUFACTURING
THE SAME
Abstract
A multilayer ceramic electronic component includes: a ceramic
body including dielectric layers and internal electrodes, stacked
to be alternately exposed to one end surface and the other end
surface of the ceramic body, with each of the dielectric layers
interposed therebetween; and external electrodes disposed on outer
surfaces of the ceramic body. The external electrodes include
electrode layers connected to the internal electrodes, electrically
insulating layers disposed on the electrode layers, and plating
layers disposed on one surface of the ceramic body in a thickness
direction of the ceramic body and connected to the electrode
layers, respectively, and the electrode layers contain nickel.
Inventors: |
PARK; Yong; (Suwon-si,
KR) ; HONG; Ki Pyo; (Suwon-si, KR) ; RYU; Jin
Yung; (Suwon-si, KR) ; CHOI; Jae Yeol;
(Suwon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRO-MECHANICS CO., LTD. |
Suwon-si |
|
KR |
|
|
Family ID: |
61281675 |
Appl. No.: |
15/493619 |
Filed: |
April 21, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01G 4/232 20130101;
H01G 4/2325 20130101; H01G 4/12 20130101; H01G 4/012 20130101; H01G
4/30 20130101 |
International
Class: |
H01G 4/30 20060101
H01G004/30; H01G 4/012 20060101 H01G004/012; H01G 4/232 20060101
H01G004/232; H01G 4/12 20060101 H01G004/12 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2016 |
KR |
10-2016-0115663 |
Claims
1. A multilayer ceramic electronic component comprising: a ceramic
body including dielectric layers, and internal electrodes stacked
in a thickness direction to be alternately exposed to one end
surface and the other end surface of the ceramic body, with one of
the dielectric layers interposed therebetween; and external
electrodes disposed on outer surfaces of the ceramic body, wherein
the external electrodes include electrode layers connected to the
internal electrodes, electrically insulating layers disposed on the
electrode layers, and plating layers disposed on one surface of the
ceramic body in the thickness direction of the ceramic body and
connected to the electrode layers, respectively, and the electrode
layers contain nickel.
2. The multilayer ceramic electronic component of claim 1, further
comprising seed layers, electrically connected to the electrode
layers, disposed on the one surface of the ceramic body in the
thickness direction of the ceramic body, wherein the plating layers
are disposed on the seed layers.
3. The multilayer ceramic electronic component of claim 2, wherein
the seed layers are disposed only on the one surface of the ceramic
body in the thickness direction of the ceramic body.
4. The multilayer ceramic electronic component of claim 1, wherein
0.8.ltoreq.T2/T1.ltoreq.1.2, in which T1 is a thickness of each of
the electrode layers in a central region of the ceramic body in the
thickness direction of the ceramic body, and T2 is a thickness of
each of the electrode layers at a point at which an outermost
internal electrode among the internal electrodes is positioned.
5. The multilayer ceramic electronic component of claim 4, wherein
0.4.ltoreq.T3/T1.ltoreq.1.0, in which T3 is a thickness of each of
the electrode layers in corner portions of the ceramic body.
6. The multilayer ceramic electronic component of claim 1, wherein
the one surface of the ceramic body in the thickness direction of
the ceramic body is a mounting surface of the multilayer ceramic
electronic component mounted on a board.
7. A method of manufacturing a multilayer ceramic electronic
component, the method comprising: preparing a plurality of ceramic
sheets; forming internal electrode patterns on the respective
ceramic sheets using a conductive paste; stacking the ceramic
sheets on which the internal electrode patterns are formed to form
a ceramic body including internal electrodes disposed therein to
face each other; forming electrode layers by transferring a
nickel-containing sheet onto both end surfaces of the ceramic body
in a length direction of the ceramic body so as to be connected to
the internal electrodes, respectively; forming electrically
insulating layers by attaching a ceramic sheet on which an
electrically insulating sheet is formed to the electrode layers,
respectively; and preparing external electrodes by forming plating
layers on one surface of the ceramic body in a thickness direction
of the ceramic body, to be connected to the electrode layers,
respectively.
8. The method of claim 7, further comprising forming seed layers
formed on the one surface of the ceramic body in the thickness
direction of the ceramic body, to be electrically connected to the
electrode layers, wherein the plating layers are disposed on the
seed layers.
9. The method of claim 8, wherein the seed layers are formed only
on the one surface of the ceramic body in the thickness direction
of the ceramic body.
10. The method of claim 7, wherein, after forming the electrode
layers and the electrically insulating layers, the ceramic body,
the electrode layers, and the electrically insulating layers are
sintered simultaneously.
11. The method of claim 7, wherein the nickel-containing sheet for
forming the electrode layers is stacked on the ceramic sheet for
forming an electrically insulating film, such that the electrode
layers and the electrically insulating layers are formed
simultaneously on each end surface of the ceramic body in the
length direction of the ceramic body.
12. The method of claim 11, wherein, after forming the electrode
layers and the electrically insulating layers, the ceramic body,
the electrode layers, and the electrically insulating layers are
sintered simultaneously.
13. The method of claim 7, wherein the one surface of the ceramic
body in the thickness direction of the ceramic body is a mounting
surface of the multilayer ceramic electronic component mounted on a
board.
14. The method of claim 7, wherein 0.8.ltoreq.T2/T1.ltoreq.1.2, in
which T1 is a thickness of each of the electrode layers in a
central region of the ceramic body in the thickness direction of
the ceramic body, and T2 is a thickness of each of the electrode
layers at a point at which an outermost internal electrode among
the internal electrodes is positioned.
15. The method of claim 14, wherein 0.4.ltoreq.T3/T1.ltoreq.1.0, in
which T3 is a thickness of each of the electrode layers in corner
portions of the ceramic body.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims benefit of priority to Korean Patent
Application No. 10-2016-0115663 filed on Sep. 8, 2016 in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to a multilayer ceramic
electronic component and a method of manufacturing the same.
BACKGROUND
[0003] In accordance with the recent trend toward miniaturization
of electronic products, multilayer ceramic electronic components
have also been required to have a small size and large
capacitance.
[0004] Therefore, various methods for decreasing thicknesses of
dielectric layers and internal electrodes and increasing the number
of dielectric layers and internal electrodes have been attempted,
and, recently, the number of multilayer ceramic electronic
components, in which thicknesses of dielectric layers are decreased
and the number of stacked dielectric layers is increased, that have
been manufactured, has continued to increase.
[0005] In addition, as external electrodes have also been required
to have a decreased thickness, a problem in which a plating
solution permeating the multilayer ceramic electronic component
through the external electrodes having the decreased thickness may
occur, such that it is technically difficult to miniaturize the
multilayer ceramic electronic component.
[0006] In particular, in a case in which shapes of the external
electrodes are non-uniform, a risk that the plating solution will
penetrate into thin portions of the external electrodes is further
increased, such that a problem occurs in securing reliability.
[0007] Meanwhile, in a case of forming the external electrodes by
an existing dipping method, or the like, which is a method of
forming the external electrodes, the external electrodes are formed
on all head surfaces, corresponding to end surfaces of a body in a
length direction of the body, and four surfaces (hereinafter,
referred to as "band surfaces") contacting the head surfaces, and
it is difficult to uniformly apply a paste for an external
electrode, due to generation of dispersion in the body and fluidity
and viscosity of the paste, such that a difference in a thickness
of the applied paste is generated.
[0008] In addition, the plating solution penetrates into a portion
in which the paste is thinly applied, due to a decrease in density
of the portion, such that reliability is reduced, and glass beading
or blistering, when glass is exposed to a surface, is generated in
a portion in which the paste is thickly applied, such that a
thickness of a plating layer should be increased in order to solve
a plating defect and a shape defect.
[0009] Therefore, when an application thickness of the external
electrode is thin and uniform, a formation area of the internal
electrodes may be increased, such that capacitance may be
significantly increased, as compared to an existing capacitor
having the same size. Therefore, research into the technology
described above has been required.
SUMMARY
[0010] An aspect of the present disclosure may provide a
high-capacitance multilayer ceramic electronic component, of which
external electrodes have a thin and uniform thickness, and a method
of manufacturing the same.
[0011] According to an aspect of the present disclosure, a
multilayer ceramic electronic component may include: a ceramic body
including dielectric layers and internal electrodes stacked to be
alternately exposed to one end surface and the other end surface of
the ceramic body, with each of the dielectric layers interposed
therebetween; and external electrodes disposed on outer surfaces of
the ceramic body, wherein the external electrodes include electrode
layers connected to the internal electrodes, electrically
insulating layers disposed on the electrode layers, and plating
layers disposed on one surface of the ceramic body in a thickness
direction of the ceramic body and connected to the electrode
layers, respectively, and the electrode layers contain nickel.
[0012] According to another aspect of the present disclosure, a
method of manufacturing a multilayer ceramic electronic component
may include: preparing a plurality of ceramic sheets; forming
internal electrode patterns on the respective ceramic sheets using
a conductive paste; stacking the ceramic sheets on which the
internal electrode pattern is formed to form a ceramic body
including internal electrodes disposed therein to face each other;
forming electrode layers by transferring a nickel-containing sheet
on both end surfaces of the ceramic body in a length direction of
the ceramic body so as to be connected to the internal electrodes,
respectively; forming electrically insulating layers by attaching a
ceramic sheet for forming an electrically insulating layer to the
electrode layers, respectively; and preparing external electrodes
by forming plating layers on one surface of the ceramic body in a
thickness direction of the ceramic body, to be connected to the
electrode layers, respectively.
BRIEF DESCRIPTION OF DRAWINGS
[0013] The above and other aspects, features, and advantages of the
present disclosure will be more clearly understood from the
following detailed description when taken in conjunction with the
accompanying drawings, in which:
[0014] FIG. 1 is a perspective view illustrating a multilayer
ceramic electronic component according to an exemplary embodiment
in the present disclosure;
[0015] FIG. 2 is a cross-sectional view taken along line I-I' of
FIG. 1;
[0016] FIG. 3 is an enlarged view of region A of FIG. 2;
[0017] FIG. 4 is a view illustrating a process of forming external
electrodes of the multilayer ceramic electronic component according
to the exemplary embodiment in the present disclosure; and
[0018] FIG. 5 is a view illustrating a process of forming external
electrodes of a multilayer ceramic electronic component according
to another exemplary embodiment in the present disclosure.
DETAILED DESCRIPTION
[0019] Hereinafter, exemplary embodiments of the present disclosure
will be described in detail with reference to the accompanying
drawings.
[0020] Directions of a hexahedron will be defined in order to
clearly describe exemplary embodiments in the present disclosure.
L, W and T, as illustrated in the drawings, refer to a length
direction, a width direction, and a thickness direction,
respectively. Here, the thickness direction may be the same as a
stacking direction in which dielectric layers are stacked.
[0021] Multilayer Ceramic Electronic Component
[0022] Hereinafter, a multilayer ceramic electronic component
according to an exemplary embodiment in the present disclosure,
and, particularly, a multilayer ceramic capacitor, will be
described. However, the multilayer ceramic electronic component
according to the present disclosure is not limited thereto.
[0023] FIG. 1 is a perspective view illustrating a multilayer
ceramic electronic component according to an exemplary embodiment
in the present disclosure, FIG. 2 is a cross-sectional view taken
along line I-I' of FIG. 1, and FIG. 3 is an enlarged view of region
A of FIG. 2.
[0024] Referring to FIGS. 1 through 3, a multilayer ceramic
electronic component 100 according to the exemplary embodiment in
the present disclosure may include a ceramic body 110, internal
electrodes 121 and 122, and external electrodes 131 and 132.
[0025] The ceramic body 110 may be formed of a hexahedron having
both end surfaces in a length (L) direction, both side surfaces in
a width (W) direction, and both side surfaces in a thickness (T)
direction. The ceramic body 110 may be formed by stacking a
plurality of dielectric layers 111 in the thickness (T) direction
and then sintering the plurality of dielectric layers 111. A shape
and a dimension of the ceramic body 110 and the number of stacked
dielectric layers 111 are not limited to those of an example
illustrated in the present exemplary embodiment.
[0026] In addition, the plurality of dielectric layers 111 forming
the ceramic body 110 may be in a sintered state, and adjacent
dielectric layers 111 may be integrated with each other so that
boundaries therebetween are not readily apparent without using a
scanning electron microscope (SEM).
[0027] A thickness of the dielectric layer 111 may be arbitrarily
changed, in accordance with a capacitance design of the multilayer
ceramic electronic component 100, and the dielectric layer 111 may
contain ceramic powders having a high dielectric constant, such as
barium titanate (BaTiO.sub.3) based powders or strontium titanate
(SrTiO.sub.3) based powders. However, a material of the dielectric
layer 111 according to the present disclosure is not limited
thereto. Further, various ceramic additives, an organic solvent, a
plasticizer, a binder, a dispersant, and the like, may be added to
the ceramic powders, according to the object of the present
disclosure.
[0028] An average particle size of ceramic powder used to form the
dielectric layer 111 is not particularly limited and may be
controlled in order to achieve the object of the present
disclosure. For example, the average particle size may be
controlled to be 400 nm or less.
[0029] The internal electrodes 121 and 122 may include a plurality
of first internal electrodes 121 and second internal electrodes 122
provided in pairs and having different polarities, and may be
formed at a predetermined thickness, with each of the plurality of
dielectric layers 111 interposed therebetween, the plurality of
dielectric layers 111 being stacked in the thickness (T) direction
of the ceramic body 110.
[0030] The first internal electrodes 121 and the second internal
electrodes 122 may be formed in a stacking direction of the
dielectric layers 111 to be alternately exposed to one end surface
and the other end surface of the ceramic body 110 in the length (L)
direction of the ceramic body 110 and formed of a conductive paste
containing a conductive metal printed thereon, and may be
electrically insulated from each other by each of the dielectric
layers 111 disposed therebetween.
[0031] That is, the first and second internal electrodes 121 and
122 may be electrically connected to the first and second external
electrodes 131 and 132 formed on both end surfaces of the ceramic
body 110 in the length (L) direction of the ceramic body 110
through portions alternately exposed to both end surfaces of the
ceramic body 110 in the length direction of the ceramic body 110,
respectively.
[0032] Therefore, when voltages are applied to the first and second
external electrodes 131 and 132, electric charges may be
accumulated between the first and second internal electrodes 121
and 122 facing each other. In this case, capacitance of the
multilayer ceramic capacitor 100 may be proportional to an area of
a region in which the first and second internal electrodes 121 and
122 overlap each other.
[0033] That is, when the area of the region in which the first and
second internal electrodes 121 and 122 overlap each other is
significantly increased, capacitance may be significantly
increased, even in a capacitor having the same size.
[0034] According to the exemplary embodiment, since thicknesses of
the external electrodes are thin and uniform, an area in which the
internal electrodes overlap each other may be significantly
increased, such that a high-capacitance multilayer ceramic
capacitor may be implemented.
[0035] Widths of the first and second internal electrodes 121 and
122 may be determined depending on a use of the multilayer ceramic
capacitor. For example, the widths of the first and second internal
electrodes 121 and 122 may be determined to be in a range of 0.2 to
1.0 .mu.m, in consideration of a size of the ceramic body 110.
However, the widths of the first and second internal electrodes 121
and 122 according to the present disclosure are not limited
thereto.
[0036] In addition, the conductive metal contained in the
conductive paste forming the first and second internal electrodes
121 and 122 may be nickel (Ni), copper (Cu), palladium (Pd), silver
(Ag), lead (Pb), or platinum (Pt) or alloys thereof. However, the
conductive metal according to the present disclosure is not limited
thereto.
[0037] The external electrodes 131 and 132 may include a first
external electrode 131 and a second external electrode 132 disposed
on outer surfaces of the ceramic body 110.
[0038] The external electrodes 131 and 132 may include first and
second electrode layers 131a and 132a, electrically insulating
layers 131b and 132b, and plating layers 131c and 132c, as
illustrated in FIG. 2.
[0039] Further, the external electrodes 131 and 132 may include
seed layers 135 and 136, disposed on one surface of the ceramic
body 110 in the thickness direction of the ceramic body 110.
[0040] The first external electrode 131 may include the first
electrode layer 131a electrically connected to the first internal
electrode 121, the electrically insulating layer 131b disposed on
the first electrode layer 131a, and the plating layer 131c disposed
on one surface of the ceramic body 110 in the thickness direction
of the ceramic body 110 and connected to the first electrode layer
131a.
[0041] Further, the second external electrode 132 may include the
second electrode layer 132a electrically connected to the second
internal electrode 122, the electrically insulating layer 132b
disposed on the second electrode layer 132a, and the plating layer
132c disposed on one surface of the ceramic body 110 in the
thickness direction of the ceramic body 110 and connected to the
second electrode layer 132a.
[0042] The first and second seed layers 135 and 136 electrically
connected to the first and second electrode layers 131a and 132a
may be further disposed on one surface of the ceramic body 110 in
the thickness direction of the ceramic body 110.
[0043] Further, the plating layers 131c and 132c may be disposed on
the seed layers 135 and 136.
[0044] The seed layers 135 and 136 may be formed at a predetermined
thickness on one surface of the ceramic body 110 in the thickness
(T) direction of the ceramic body 110 by sputtering or depositing a
conductive metal, and may be divided and formed on both end
portions, respectively, of one surface of the ceramic body 110 in
the thickness (T) direction of the ceramic body 110.
[0045] The seed layers 135 and 136 may also be formed on one
surface of the ceramic body 110 in the thickness (T) direction of
the ceramic body 110 by printing a conductive paste containing a
conductive metal.
[0046] The conductive metal forming the seed layers 135 and 136 may
be the same as that used in the first and second internal
electrodes 121 and 122, but is not limited thereto. For example,
the conductive metal may be copper (Cu), nickel (Ni), palladium
(Pd), platinum (Pt), gold (Au), silver (Ag), lead (Pb), or alloys
thereof.
[0047] As a method of forming an external electrode used in the
related art, a method of dipping the ceramic body 110 in a paste
containing a metal ingredient has principally been used.
[0048] In a case in which the external electrode is formed by the
dipping method, the paste is not uniformly applied due to fluidity
and viscosity of the paste, such that there is a difference in
application thickness between a central portion and a corner
portion of the external electrode.
[0049] In a case in which the thickness of the external electrode
is not uniform, as described above, glass beading or blister is
generated in the central portion, in which the paste is applied in
a thicker thickness than that of an edge portion, which may cause a
plating defect and a shape defect, and the corner portion in which
the paste is applied in a thin thickness is vulnerable to
permeation of a plating solution, such that reliability is
deteriorated.
[0050] In addition, in a case of complementing the corner portion
vulnerable to the plating solution, a thickness of the central
portion in which the paste is applied may be increased, and there
is a limitation in increasing a size of a ceramic capacitor in
order to increase capacitance.
[0051] According to the exemplary embodiment, the first and second
external electrodes 131 and 132 may include the first and second
electrode layers 131a and 132a electrically connected to the first
and second internal electrodes 121 and 122, the electrically
insulating layers 131b and 132b disposed on the first and second
electrode layers 131a and 132a, and the plating layers 131c and
132c disposed on one surface of the ceramic body 110 in the
thickness direction of the ceramic body 110 and connected to the
first and second electrode layers 131a and 132a, respectively.
[0052] The seed layers 135 and 136 electrically connected to the
first and second electrode layers 131a and 132a may be further
disposed on one surface of the ceramic body 110 in the thickness
direction of the ceramic body 110.
[0053] Further, the plating layers 131c and 132c may be disposed on
the seed layers 135 and 136.
[0054] The first and second electrode layers 131a and 132a may be
disposed on both end surfaces of the ceramic body 110 in the length
(L) direction of the ceramic body 110, respectively, among outer
surfaces of the ceramic body 110. However, the first and second
electrode layers 131a and 132a are not limited thereto.
[0055] Therefore, the first and second electrode layers 131a and
132a may be disposed on both end surfaces of the ceramic body 110
in the length (L) direction of the ceramic body 110, respectively,
and the electrically insulating layers 131b and 132b may be
disposed on the first and second electrode layers 131a and
132a.
[0056] According to the exemplary embodiment, the first and second
electrode layers 131a and 132a may be disposed on both end surfaces
of the ceramic body 110 in the length (L) direction of the ceramic
body 110, respectively, and may also be extended onto portions of
both surfaces of the ceramic body 110 in the thickness direction of
the ceramic body 110, respectively.
[0057] Since the first and second electrode layers 131a and 132a
are not formed by the dipping method used in the related art, but
are formed by transferring a sheet containing a conductive metal,
the first and second electrode layers 131a and 132a may be formed
on head surfaces corresponding to the end surfaces of the ceramic
body 110 in the length (L) direction of the ceramic body 110, and
may or may not be formed at sizes as small as possible on all band
surfaces, corresponding to the four surfaces contacting the head
surfaces.
[0058] Therefore, the thicknesses of the external electrodes
disposed on the outer surfaces of the ceramic body may be thin and
uniform.
[0059] Thus, since the thicknesses of the external electrodes
disposed on the outer surfaces of the ceramic body are thin and
uniform, formation areas of the internal electrodes may be
increased, such that areas in which the internal electrodes overlap
each other may be significantly increased, whereby a
high-capacitance multilayer ceramic capacitor may be
implemented.
[0060] According to the exemplary embodiment, the first and second
electrode layers 131a and 132a may be formed by a sheet transfer
method or a pad transfer method, detailed contents of which will be
described below, and unlike the dipping method used in the related
art.
[0061] In particular, according to the exemplary embodiment, the
first and second electrode layers 131a and 132a may be formed by
the sheet transfer method or the pad transfer method, to thereby be
disposed on both end surfaces of the ceramic body 110 in the length
direction of the ceramic body 110, and the electrically insulating
layers may be disposed thereon by transferring a ceramic sheet for
forming an electrically insulating layer, such that at the time of
mounting the electronic component on a board, a structure in which
solder is not disposed on the end surfaces of the electronic
component but is disposed only on a mounting surface of the
electronic component may be implemented, whereby a mounting density
may be increased.
[0062] That is, the first and second electrode layers 131a and 132a
may be disposed on both ends of the ceramic body 110 in the length
(L) direction of the ceramic body 110, the electrically insulating
layers 131b and 132b may be disposed on the first and second
electrode layers 131a and 132a, the seed layers 135 and 136
electrically connected to the first electrode layers 131a and 132a
may be further disposed on one surface of the ceramic body in the
thickness direction of the ceramic body, corresponding to the
mounting surface at the time of mounting the electronic component
on the board, and the plating layers 131c and 132c may be disposed
on the seed layers 135 and 136, such that a mounting area may be
decreased, as compared to the related art.
[0063] Referring to FIGS. 2 and 3, a structure in which the first
and second electrode layers 131a and 132a and the electrically
insulating layers 131b and 132b may be disposed on both end
surfaces of the ceramic body 110 in the length direction of the
ceramic body 110, and the seed layers 135 and 136 and the plating
layers 131c and 132c connected to the first and second electrode
layers 131a and 132a are disposed on one surface of the ceramic
body 110 in the thickness direction of the ceramic body 110, is
illustrated.
[0064] According to the exemplary embodiment, the first and second
electrode layers 131a and 132a may contain nickel (Ni).
[0065] Since the first and second electrode layers 131a and 132a in
the external electrodes 131 and 132 may contain nickel, hermetic
sealing of the ceramic body 110 may be improved, such that
deterioration of reliability due to permeation of the plating
solution may be prevented.
[0066] The plating layers 131c and 132c may be disposed on the seed
layers 135 and 136.
[0067] That is, the plating layers 131c and 132c may be disposed on
the seed layers 135 and 136, disposed on one surface of the ceramic
body 110 in the thickness (T) direction of the ceramic body 110
corresponding to the mounting surface, at the time of mounting the
electronic component on the board.
[0068] In particular, according to the exemplary embodiment, since
the first and second electrode layers 131a and 132a are formed by
the sheet transfer method instead of the dipping method used in the
related art, and the electrically insulating layers 131b and 132b
are formed by transferring the ceramic sheet for forming an
electrically insulating layer thereon, the first and second
electrode layers and the electrically insulating layers may be
disposed on the head surfaces of the ceramic body 110, which are
the end surfaces of the ceramic body 110 in the length (L)
direction of the ceramic body 110, and the seed layers 135 and 136
and the plating layers 131c and 132c may be disposed on one surface
of the ceramic body 110 in the thickness (T) direction of the
ceramic body 110.
[0069] Therefore, the plating layers 131c and 132c may be formed on
one surface of the ceramic body 110 in the thickness (T) direction
of the ceramic body 110 but are not formed on both end surfaces of
the ceramic body 110 in the length direction and on both side
surfaces of the ceramic body 110 in the width direction.
[0070] The plating layers 131c and 132c may be nickel plating
layers and tin plating layers, but are not limited thereto.
[0071] Referring to FIG. 3, when a thickness of each of the first
and second electrode layers 131a and 132a in a central region of
the ceramic body 110, and in the thickness direction of the ceramic
body 110 is T1, and a thickness of each of the first and second
electrode layers 131a and 132a, at a point at which an outermost
internal electrode 121 or 122 among the internal electrodes 121 and
122 is positioned, is T2, 0.8.ltoreq.T2/T1.ltoreq.1.2.
[0072] The thickness T1 of each of the first and second electrode
layers 131a and 132a in the central region of the ceramic body 110,
in the thickness direction of the ceramic body 110, refers to a
thickness of each of the first and second electrode layers 131a and
132a, at a point at which a virtual line drawn in the length
direction of the ceramic body 110, from a central point of the
ceramic body 110 in the thickness direction of the ceramic body
110, meets the end surface of the ceramic body 110.
[0073] Likewise, the thickness T2 of each of the first and second
electrode layers 131a and 132a, at the point at which the outermost
internal electrode 121 or 122 among the internal electrodes 121 and
122 is positioned, refers to a thickness of each of the first and
second electrode layers 131a and 132a, at a point at which a
virtual line drawn in the length direction of the ceramic body 110
from a position of an internal electrode disposed in the outermost
portion of the ceramic body 110, in the thickness direction of the
ceramic body 110, will meet the end surface of the ceramic body
110.
[0074] 0.8.ltoreq.T2/T1.ltoreq.1.2 may be satisfied to reduce a
deviation between the thickness T1 of each of the first and second
electrode layers 131a and 132a in the central region of the ceramic
body 110, in the thickness direction of the ceramic body 110, and
the thickness T2 of each of the first and second electrode layers
131a and 132a, at the point at which the outermost internal
electrode 121 or 122 among the internal electrodes 121 and 122 is
positioned, whereby a deterioration of reliability may be
prevented.
[0075] In a case in which T2/T1 is less than 0.8 or exceeds 1.2, a
deviation between thicknesses of the first and second electrode
layers 131a and 132a is large, such that a plating solution may
penetrate into a portion having a thin thickness, thereby
deteriorating reliability.
[0076] According to the exemplary embodiment, when a thickness of
each of the first and second electrode layers 131a and 132a in
corner portions of the ceramic body 110 is T3,
0.4.ltoreq.T3/T1.ltoreq.1.0.
[0077] The thickness T3 of each of the first and second electrode
layers 131a and 132a in the corner portions of the ceramic body 110
refers to a thickness of each of the first and second electrode
layers 131a and 132a formed in corner regions of the ceramic body
110, and is the thickness along the diagonal direction of the
ceramic body 110.
[0078] 0.4.ltoreq.T3/T1.ltoreq.1.0 may be satisfied to reduce a
deviation between the thickness T1 of each of the first and second
electrode layers 131a and 132a in the central region of the ceramic
body 110, in the thickness direction of the ceramic body 110, and
the thickness T3 of each of the first and second electrode layers
131a and 132a in the corner portions of the ceramic body 110,
whereby deterioration of reliability may be prevented.
[0079] In a case in which T3/T1 is less than 0.4 or exceeds 1.0, a
deviation between thicknesses of the first and second electrode
layers 131a and 132a is large, such that a plating solution may
penetrate into a portion having a thin thickness, thereby
deteriorating reliability.
[0080] Method of Manufacturing Multilayer Ceramic Electronic
Component
[0081] In the method of manufacturing a multilayer ceramic
electronic component according to the exemplary embodiment, first,
slurry containing powders such as barium titanate (BaTiO.sub.3)
powders, or the like, may be applied onto carrier films and dried
to prepare a plurality of ceramic sheets, thereby forming
dielectric layers.
[0082] The ceramic sheets may be manufactured by mixing ceramic
powders, a binder, and a solvent with each other to prepare slurry,
and manufacturing the slurry in a form of sheets having a thickness
of several micrometers by a doctor blade method.
[0083] Then, a conductive paste containing conductive metal powders
may be prepared. The conductive metal powders may be formed of
nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), lead (Pb),
or platinum (Pt), or alloys thereof, and have an average particle
size of 0.1 to 0.2 .mu.m, and a conductive paste for an internal
electrode containing 40 wt % to 50 wt % of the conductive metal
powders may be prepared.
[0084] The conductive paste for an internal electrode may be
applied to the ceramic sheets by a printing method, or the like, to
form internal electrode patterns. A method of printing the
conductive paste may be a screen printing method, a gravure
printing method, or the like, but is not limited thereto. Two
hundred or three hundred ceramic sheets on which the internal
electrode pattern is printed may be stacked, pressed, and sintered,
such that a ceramic body may be manufactured.
[0085] FIG. 4 is a view illustrating a process of forming external
electrodes of the multilayer ceramic electronic component according
to the exemplary embodiment in the present disclosure.
[0086] Referring to FIG. 4, the first and second electrode layers
131a and 132a may be formed by transferring a nickel-containing
sheet 130 onto both end surfaces of the ceramic body 110 in the
length direction of the ceramic body 110, so as to be connected to
the internal electrodes.
[0087] The method of forming the first and second electrode layers
may be performed by forming the first electrode layer on one end
surface of the ceramic body and then forming the second electrode
layer on the other end surface of the ceramic body, and
electrically insulating layers, to be described below, may be
formed by the same method.
[0088] Hereinafter, a method of forming the first electrode layer
and the electrically insulating layer on one end surface of the
ceramic body will be described, and this method may also be equally
applied at the time of forming the second electrode layer and the
electrically insulating layer on the other end surface of the
ceramic body.
[0089] The nickel-containing sheet 130 may be formed by applying a
conductive metal paste containing nickel on a polyethylene
terephthalate (PET) film 150.
[0090] After preparing the nickel-containing sheet 130, which has
been attached to the PET film, one end surface of the ceramic body
110 in the length direction of the ceramic body 110 may be made to
closely adhere to the nickel-containing sheet 130 by applying a
pressure to the nickel-containing sheet 130, such that the
nickel-containing sheet 130 may be transferred to both end surfaces
of the ceramic body 110 in the length direction of the ceramic
body, so as to be connected to the internal electrodes, thereby
forming the first and second electrode layers 131a and 132a.
[0091] In this case, the sheet may be attached to the ceramic body
so as to be extended from the head surfaces of the ceramic body,
which are the end surfaces of the ceramic body 110 in the length
direction of the ceramic body, to band surfaces of the ceramic
body, by applying heat to the PET film 150, to increase flexibility
of the nickel-containing sheet 130, and, at the same time,
improving adhesion between the body and sheet.
[0092] Next, in order to remove an unnecessary portion of the sheet
attached to the ceramic body, the ceramic body 110 to which the
nickel-containing sheet 130 is attached is pressed through the PET
film 150, such that a portion of the sheet that is not attached to
the body may be removed by elasticity.
[0093] Here, the nickel-containing sheet 130 may be cut by the PET
film at corner portions of the ceramic body, and at the time of
removing pressure, the nickel-containing sheet 130 may be attached
only to the head surfaces of the ceramic body.
[0094] In this case, portions of the sheets that are not attached
to the ceramic body remain on the PET films, such that a separate
process of removing unnecessary sheets may be omitted.
[0095] According to the method described above, the first and
second electrode layers may be formed on the head surfaces,
corresponding to both end surfaces of the ceramic body in the
length direction of the ceramic body, and thicknesses of the
external electrodes may be decreased, whereby a high-capacitance
multilayer ceramic capacitor may be implemented.
[0096] Then, the electrically insulating layers 131b and 132b may
be formed by attaching a ceramic sheet 140 for forming an
electrically insulating layer to the first and second electrode
layers 131a and 132a.
[0097] The ceramic sheet 140 for forming an electrically insulating
layer may be attached onto the PET film 150.
[0098] After preparing the ceramic sheet 140 for forming an
electrically insulating layer, attached onto the PET film 150, the
electrically insulating layers 131b and 132b may be formed on the
first and second electrode layers 131a and 132a by causing one end
surface of the ceramic body 110 in the length direction of the
ceramic body to closely adhere to the ceramic sheet 140 for forming
an electrically insulating layer, while applying a pressure.
[0099] Next, in order to remove an unnecessary portion of the sheet
attached to the ceramic body, the ceramic body 110 to which the
ceramic sheet 140 for forming an electrically insulating layer is
attached is pressed through the PET film 150, such that a portion
of the sheet that is not attached to the body may be removed by
elasticity.
[0100] Here, the ceramic sheet 140 for forming an electrically
insulating layer may be cut by the PET film at the corner portions
of the ceramic body, and at the time of removing pressure, the
sheet 140 for forming an electrically insulating layer may be
attached only to the head surfaces of the ceramic body.
[0101] In this case, portions of the sheets that are not attached
onto the ceramic body remain on the PET films, such that a separate
process of removing unnecessary sheets may be omitted.
[0102] According to the exemplary embodiment, the first and second
electrode layers 131a and 132a may be formed by the sheet transfer
method or the pad transfer method to thereby be disposed on both
end surfaces of the ceramic body 110 in the length direction of the
ceramic body 110, and the electrically insulating layers 131b and
132b may be disposed on the first electrodes 131a and 132a by
transferring the ceramic sheet for forming an electrically
insulating layer, such that at the time of mounting the electronic
component on a board, a structure in which solder is not disposed
on the side surfaces of the electronic component but is disposed
only on amounting surface of the electronic component may be
implemented, whereby a mounting density may be increased.
[0103] Next, seed layers 135 and 136 may be formed on one surface
of the ceramic body 110 in the thickness (T) direction of the
ceramic body 110, and the plating layers 131c and 132c may be
formed thereon.
[0104] In particular, according to the exemplary embodiment in the
present disclosure, since the first and second electrode layers
131a and 132a are not formed by the dipping method used in the
related art, the first and second electrode layers 131a and 132a
may be formed on the head surfaces corresponding to the end
surfaces of the ceramic body 110 in the length (L) direction of the
ceramic body 110, and the seed layers 135 and 136 and the plating
layers 131c and 132c may be formed on one surface of the ceramic
body 110 in the thickness (T) direction of the ceramic body 110,
corresponding to the mounting surface at the time of mounting the
electronic component on the board.
[0105] A method of forming the seed layers 135 and 136 may be, for
example a screen printing method, a gravure printing method, or the
like. However, the method of forming the seed layers is not limited
thereto, but may also be a sputtering method or a depositing
method.
[0106] The plating layers 131c and 132c may be nickel plating
layers and tin plating layers disposed on the nickel plating
layers, but are not limited thereto.
[0107] According to the exemplary embodiment, after forming the
first and second electrode layers 131a and 132a and the
electrically insulating layers 131b and 132b, the ceramic body 110,
the first and second electrode layers 131a and 132a, and the
electrically insulating layers 131b and 132b may be sintered
simultaneously.
[0108] Since the first and second electrode layers 131a and 132a
and the electrically insulating layers 131b and 132b are formed by
the sheet transfer method or the pad transfer method instead of the
dipping method used in the related art, the ceramic body may be in
a green chip state.
[0109] That is, after forming the first and second electrode layers
131a and 132a and the electrically insulating layers 131b and 132b,
the ceramic body 110, the first and second electrode layers 131a
and 132a, and the electrically insulating layers 131b and 132b may
be sintered simultaneously.
[0110] Therefore, as compared to a method of separately sintering
external electrodes used in the related art, a manufacturing
process may be simplified, whereby productivity may be
improved.
[0111] FIG. 5 is view illustrating a process of forming external
electrodes of a multilayer ceramic electronic component according
to another exemplary embodiment in the present disclosure.
[0112] Referring to FIG. 5, in a method of forming the external
electrodes of the multilayer ceramic electronic component according
to another exemplary embodiment in the present disclosure, first
and second electrode layers 131a and 132a and electrically
insulating layers 131b and 132b may be simultaneously transferred
to both end surfaces of the ceramic body 110, unlike the method of
forming the external electrodes of the multilayer ceramic
electronic component according to the exemplary embodiment in the
present disclosure.
[0113] That is, a ceramic sheet 140 for forming an electrically
insulating layer may be attached onto a PET film 150, and a
nickel-containing sheet 130 may be prepared by applying a
conductive metal paste containing nickel (Ni) on the ceramic sheet
140 for forming an electrically insulating layer.
[0114] After preparing a material in which the nickel-containing
sheet 130, the ceramic sheet 140 for forming an electrically
insulating layer, and the PET film 150 are sequentially stacked,
one end surface of the ceramic body 110 in the length direction of
the ceramic body 110 may be made to closely adhere, to the
nickel-containing sheet 130 by applying a pressure to the
nickel-containing sheet 130 so that the pressure is applied up to
the ceramic sheet 140 for forming an electrically insulating layer,
such that the nickel-containing sheet 130 may be transferred to
both end surfaces of the ceramic body 110 in the length direction
of the ceramic body so as to be connected to the internal
electrodes, whereby the first electrode layer 131a and the
electrically insulating layer 131b may be formed at the same time,
and the second electrode layer 132a and the electrically insulating
layer 132b may be formed at the same time.
[0115] In this case, the sheet may be attached to the ceramic body
so as to be extended from the head surfaces of the ceramic body,
which are the end surfaces of the ceramic body 110 in the length
direction of the ceramic body, to band surfaces of the ceramic body
by applying heat to the PET film 150 to increase flexibility of the
nickel-containing sheet 130, and, at the same time, improve
adhesion between the body and sheet.
[0116] Next, in order to remove unnecessary portions of the sheets
attached to the ceramic body, the ceramic body 110 to which the
ceramic sheet 140 for forming an electrically insulating layer and
the nickel-containing sheet 130 are attached is pressed together
with the PET film 150, such that portions of the sheets that are
not attached to the body may be removed by elasticity.
[0117] Here, the ceramic sheet 140 for forming an electrically
insulating layer and the nickel-containing sheet 130 may be cut by
the PET film at corner portions of the ceramic body, and, at the
time of removing pressure, the ceramic sheet 140 for forming an
electrically insulating layer and the nickel-containing sheet 130
may be attached only to the head surfaces of the ceramic body.
[0118] In this case, portions of the sheets that are not attached
to the ceramic body remain on the PET films, such that a separate
process of removing unnecessary sheets may be omitted.
[0119] According to the method described above, the first and
second electrode layers may be formed only on the head surfaces,
corresponding to both end surfaces of the ceramic body in the
length direction of the ceramic body, and thicknesses of the
external electrodes may be decreased, whereby a high-capacitance
multilayer ceramic capacitor may be implemented.
[0120] According to another exemplary embodiment, after forming the
first and second electrode layers 131a and 132a and the
electrically insulating layers 131b and 132b, the ceramic body 110,
the first and second electrode layers 131a and 132a, and the
electrically insulating layers 131b and 132b may be sintered
simultaneously.
[0121] Since the first and second electrode layers 131a and 132a
and the electrically insulating layers 131b and 132b are formed by
the sheet transfer method or the pad transfer method instead of the
dipping method used in the related art, the ceramic body may be in
a green chip state.
[0122] That is, after forming the first and second electrode layers
131a and 132a and the electrically insulating layers 131b and 132b,
the ceramic body 110, the first and second electrode layers 131a
and 132a, and the electrically insulating layers 131b and 132b may
be sintered simultaneously.
[0123] Therefore, as compared to a method of separately sintering
external electrodes used in the related art, a manufacturing
process may be simplified, whereby productivity may be
improved.
[0124] Contents overlapping those described in the multilayer
ceramic electronic component according to the exemplary embodiment
described above will be omitted.
[0125] As set forth above, in the multilayer ceramic electronic
component according to the exemplary embodiments in the present
disclosure, the external electrodes may have a thin and uniform
thickness, and thus formation areas of the internal electrodes may
be increased, such that areas in which the internal electrodes
overlap each other may be significantly increased, whereby a
high-capacitance multilayer ceramic electronic component may be
implemented.
[0126] Further, since the first and second electrode layers of the
external electrodes contain nickel, hermetic sealing may be
improved, such that reliability may be improved.
[0127] In addition, since the electrically insulating layers are
formed by transferring the ceramic sheets onto the first and second
electrode layers disposed on both end surfaces of the ceramic body
in the length direction of the ceramic body, the structure in which
the solder is not disposed on the end surfaces but is disposed only
on the mounting surface of the ceramic body may be implemented,
whereby the mounting density may be increased.
[0128] While exemplary embodiments have been shown and described
above, it will be apparent to those skilled in the art that
modifications and variations could be made without departing from
the scope of the present invention, as defined by the appended
claims.
* * * * *